The prior art device of most particular relevance included a housing enclosing two diaphragm pumps attached to two sidewalls of the housing, two actuator arms secured by a unitary bracket to one end wall of the housing, and an electromagnet secured to the other end wall of the housing to effect reciprocal movement of the actuator arms and diaphragm to which they are attached. Devices of this type were extremely difficult to assemble properly initially and also to reassemble during repair to achieve the degree of reliability and performance that was desired. While the exact cause for the difficulties has not been isolated, it became apparent that a redesign of the device in a way which would control inter-related tolerances and assure proper alignment of the various parts with a simplified assembly procedure was required.
Among the sources of alignment difficulties with the prior art device was that the bracket which pivotally supports the actuator arms had to be positioned at exactly the right height in relationship to both of the diaphragm pumps and also had to be aligned precisely relative to the plane of movement such that the pivot points for both actuator arms permitted reciprocating motion along the line which presented the least stress to either the actuator arms or the rubber diaphragm. Another source of difficulty in alignment resulted from the normal deviations in size and shape of the component parts, drill holes, gasketing materials, and the like which, even through within commercially practical tolerances, result in cumulative deviations which inherently result in misalignment in a number of devices.
There is a present need for an improved electric air pump assembly of the type described which would be easier to assemble initially and during repair, and which would offer a greater promise of reliability and freedom from failure once assembled.